Field of the Invention
The present invention relates to a light guide plate, and a backlight unit and a liquid crystal display device including the same.
Discussion of the Related Art
A general liquid crystal display device is a light switching device, and displays an image using thin film transistors. In addition to being used as a display for televisions and computer monitors, the liquid crystal display device is widely used as a display for devices, such as notebook computers, tablet computers, smart phones, portable display devices, and portable information devices. Because the liquid crystal display device is not a self-emitting device, the liquid crystal display device displays an image using light irradiated from a backlight unit arranged below a liquid crystal display panel.
FIG. 1 is a cross-sectional view illustrating a general backlight unit. In FIG. 1, the general backlight unit includes a light guide plate 10 having a light incident portion 12, and a light emitting diode array 20. The light guide plate 10 has a rectangular shape. Here, the light guide plate 10 upwardly emits light incident from the light emitting diode array 20 onto the light incident portion 12, which is flat and provided at one side, and then internally refracts and reflects the light. Specifically, the light emitting diode array 20 is arranged at one side of the light guide plate 10 to face the light incident portion 12 of the light guide plate 10. The light emitting diode array 20 includes a plurality of light emitting diode packages 22 arranged at certain intervals. Each of the plurality of light emitting diode packages 22 irradiates light to the light incident portion 12 of the light guide plate 10 by emitting the light through a light emission surface facing the light incident portion 12 of the light guide plate 10.
Because the general backlight unit includes the light guide plate 10 having a shape restricted to a rectangular shape, light may uniformly be diffused to reach an opposite surface of the light incident portion 12 of the light guide plate 10. However, if the liquid crystal display device, the backlight unit, and the light guide plate are modified to various shapes for application to various products, light may fail to reach a specific area of the light guide plate, thereby resulting in a dark portion. For this reason, a problem may occur in that a luminance of the specific area of the light guide plate is reduced, thereby causing a deterioration in picture quality.